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Riserva Naturale Regionale di Rio Torsero |
Protected Area |
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The little valley of Rio Torsero, situated next to the town of Ceriale and crossed by a viaduct of the Autostrada dei Fiori, is not a place of great interest for the landscape. It is much more important from a paleontological point of view, since it houses a very rich fossil deposit dating back to the Pliocene period (from 5,2 to 1,8 million years ago), famous all over the world for their exceptional preservation conditions and for the abundance and the variety of its specimens. Rio Torsero dug its riverbed in the rocky formation of the Argille di Ortovero, highlighting the sedimentary strata containing the fossils. Among the latter, molluscs belonging to the bivalves and gasteropods classes prevail. Many of them are perfectly preserved, also in their most fragile parts and in the smallest details of the shell. Unfortunately the fossils of Rio Torsero are not only interesting for researches, but also for unscrupulous gatherers and traders who assaulted the deposit digging everywhere to extract as many finds as possible. To protect the deposit from other plunges, the Riserva Naturale Regionale del Rio Torsero was established in 1985. A collection of fossils coming from the deposit of Rio Torsero is housed in the premises of the school "Silvio Lai" in Peagna, a country ward of Ceriale, situated at a few hundred meters from the natural reserve. |
Fossils, the Rests of Ancient Organisms |
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The identifiable rests of vegetal or animal organisms which lived in past geological periods are called fossils. They are mainly marine organisms whose rests are deposited at the bottom of the sea and remain incorporated in the sediments which accumulated meanwhile. The series of the chemical-physical processes taking place after the inclusion of the organic rests in the sediment is called fossilization. During the fossilization, the organic substances are replaced by mineral ones which are more stable than the surrounding material. The form and the structure of the organic rests remained more or less unaltered, so that they could preserve themselves within the sedimentary rock for millions of years. In general, only the hard parts of the organisms transform themselves into fossils: shells, inner skeletons, and the wooden parts of the plants. The tender parts rapidly deteriorate and usually do not preserve themselves. Sometimes also the hard parts disappear and only the outer mark in the rock remains. Palenteology is the branch of science studying the fossils, obtaining from them essential data about the evolution of the animal and vegetal organisms during the geological periods and about the ancient environments in which the organisms lived. Moreover, fossils enable geologists to establish chronological relations between the sedimentary rocks: as a matter of fact, the more recent rocky strata contain more evolved fossil species rather than the ones found in the most ancient strata. |